Economic methods of production of polymers of aspartic acid and its salts for use as inhibitors of corrosion of ferrous metals, fertilizers, tartar barrier agents, scale inhibition agents and dispersants such as those used for clays, ores, coal, pigments, soil or minerals in dishwashing and laundry detergents, and the like, are highly desirable. These polymers are particularly useful for the prevention of scale deposition in boiler water, reverse osmosis membranes and detergents and are readily biodegradable. Scale is composed to varying degrees of the sulfate, carbonate and phosphate salts of barium, calcium and strontium and magnesium hydroxide.